title: Novel 3D-CT evaluation of carotid stent volume: greater chronological expansion of stents in patients with vulnerable plaques.
abstract: BACKGROUND
  Although self-expanding carotid stents may dilate gradually, the degrees of residual stenosis have been quantified by the NASCET criteria, which is too simple to reflect the configuration of the stented artery. We measured the volumes of the stent lumens chronologically by 3D-CT in patients after carotid artery stenting (CAS), and analyzed the correlations between the volume change and medical factors.
  
  
  METHODS
  Fourteen patients with carotid artery stenosis were treated using self-expanding, open-cell stents. All patients underwent preoperative plaque MRI (magnetization-prepared rapid acquisition gradient-echo, MPRAGE) and chronological 3D-CT examinations of their stents immediately after their placement and 1 day, 1 week, and 1 month after the procedure. The volume of the stent lumen was measured using a 3D workstation. The correlations between stent volume and various factors including the presence of underlying diseases, plaque characteristics, and the results of the CAS procedure were analyzed.
  
  
  RESULTS
  Stent volume gradually increased in each case and had increased by 1.04-1.55 (mean, 1.25)-fold at 1 postoperative month. The presence of underlying medical diseases, plaque length, the degree of residual stenosis immediately after CAS, and plaque calcification did not have an impact on the change in stent volume. On the other hand, the stent volume increase was significantly larger in the patients with vulnerable plaques that demonstrated high MPRAGE signal intensity (P < 0.05).
  
  
  CONCLUSIONS
  A 3D-CT examination is useful for precisely measuring stent volume. Self-expanding stents in carotid arteries containing vulnerable plaques expand significantly more than those without such plaques in a follow-up period.
authors.affiliation: Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, Okayama, 700-8558, Japan.
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Itami
authors.forename: Koji
authors.initials: K
authors.lastname: Tokunaga
authors.forename: Yu
authors.initials: Y
authors.lastname: Okuma
authors.forename: Tomohito
authors.initials: T
authors.lastname: Hishikawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugiu
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ida
authors.forename: Isao
authors.initials: I
authors.lastname: Date
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000792:Angiography / Q000379:methods*; D001807:Blood Vessel Prosthesis; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D019919:Prosthesis Implantation / Q000379:methods; D011856:Radiographic Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome